#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>

char* toLowerCase(char* s)
{
	for (int i = 0; i < strlen(s); i++)
	{
		if (s[i] <= 'Z' && s[i] >= 'A')
		{
			s[i] = s[i] + 32;
		}
	}
	printf("%s", s);
	return s;
}

int main()
{	
	char s[] = "HELLO";

	toLowerCase(s);
	
	return 0;
}